/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <stddef.h>
#include <stdlib.h>

#include <isc/lib.h>
#include <isc/once.h>
#include <isc/resultclass.h>
#include <isc/rwlock.h>
#include <isc/util.h>

typedef struct resulttable {
	unsigned int base;
	unsigned int last;
	const char **text;
	int set;
	ISC_LINK(struct resulttable) link;
} resulttable;

typedef ISC_LIST(resulttable) resulttable_list_t;

static const char *description[ISC_R_NRESULTS] = {
	"success",			    /*%< 0 */
	"out of memory",		    /*%< 1 */
	"timed out",			    /*%< 2 */
	"no available threads",		    /*%< 3 */
	"address not available",	    /*%< 4 */
	"address in use",		    /*%< 5 */
	"permission denied",		    /*%< 6 */
	"no pending connections",	    /*%< 7 */
	"network unreachable",		    /*%< 8 */
	"host unreachable",		    /*%< 9 */
	"network down",			    /*%< 10 */
	"host down",			    /*%< 11 */
	"connection refused",		    /*%< 12 */
	"not enough free resources",	    /*%< 13 */
	"end of file",			    /*%< 14 */
	"socket already bound",		    /*%< 15 */
	"reload",			    /*%< 16 */
	"lock busy",			    /*%< 17 */
	"already exists",		    /*%< 18 */
	"ran out of space",		    /*%< 19 */
	"operation canceled",		    /*%< 20 */
	"socket is not bound",		    /*%< 21 */
	"shutting down",		    /*%< 22 */
	"not found",			    /*%< 23 */
	"unexpected end of input",	    /*%< 24 */
	"failure",			    /*%< 25 */
	"I/O error",			    /*%< 26 */
	"not implemented",		    /*%< 27 */
	"unbalanced parentheses",	    /*%< 28 */
	"no more",			    /*%< 29 */
	"invalid file",			    /*%< 30 */
	"bad base64 encoding",		    /*%< 31 */
	"unexpected token",		    /*%< 32 */
	"quota reached",		    /*%< 33 */
	"unexpected error",		    /*%< 34 */
	"already running",		    /*%< 35 */
	"ignore",			    /*%< 36 */
	"address mask not contiguous",	    /*%< 37 */
	"file not found",		    /*%< 38 */
	"file already exists",		    /*%< 39 */
	"socket is not connected",	    /*%< 40 */
	"out of range",			    /*%< 41 */
	"out of entropy",		    /*%< 42 */
	"invalid use of multicast address", /*%< 43 */
	"not a file",			    /*%< 44 */
	"not a directory",		    /*%< 45 */
	"queue is empty",		    /*%< 46 */
	"address family mismatch",	    /*%< 47 */
	"address family not supported",	    /*%< 48 */
	"bad hex encoding",		    /*%< 49 */
	"too many open files",		    /*%< 50 */
	"not blocking",			    /*%< 51 */
	"unbalanced quotes",		    /*%< 52 */
	"operation in progress",	    /*%< 53 */
	"connection reset",		    /*%< 54 */
	"soft quota reached",		    /*%< 55 */
	"not a valid number",		    /*%< 56 */
	"disabled",			    /*%< 57 */
	"max size",			    /*%< 58 */
	"invalid address format",	    /*%< 59 */
	"bad base32 encoding",		    /*%< 60 */
	"unset",			    /*%< 61 */
	"multiple",			    /*%< 62 */
	"would block",			    /*%< 63 */
	"complete",			    /*%< 64 */
	"crypto failure",		    /*%< 65 */
	"disc quota",			    /*%< 66 */
	"disc full",			    /*%< 67 */
	"default",			    /*%< 68 */
	"IPv4 prefix",			    /*%< 69 */
	"TLS error",			    /*%< 70 */
	"ALPN for HTTP/2 failed"	    /*%< 71 */
};

static const char *identifier[ISC_R_NRESULTS] = { "ISC_R_SUCCESS",
						  "ISC_R_NOMEMORY",
						  "ISC_R_TIMEDOUT",
						  "ISC_R_NOTHREADS",
						  "ISC_R_ADDRNOTAVAIL",
						  "ISC_R_ADDRINUSE",
						  "ISC_R_NOPERM",
						  "ISC_R_NOCONN",
						  "ISC_R_NETUNREACH",
						  "ISC_R_HOSTUNREACH",
						  "ISC_R_NETDOWN",
						  "ISC_R_HOSTDOWN",
						  "ISC_R_CONNREFUSED",
						  "ISC_R_NORESOURCES",
						  "ISC_R_EOF",
						  "ISC_R_BOUND",
						  "ISC_R_RELOAD",
						  "ISC_R_LOCKBUSY",
						  "ISC_R_EXISTS",
						  "ISC_R_NOSPACE",
						  "ISC_R_CANCELED",
						  "ISC_R_NOTBOUND",
						  "ISC_R_SHUTTINGDOWN",
						  "ISC_R_NOTFOUND",
						  "ISC_R_UNEXPECTEDEND",
						  "ISC_R_FAILURE",
						  "ISC_R_IOERROR",
						  "ISC_R_NOTIMPLEMENTED",
						  "ISC_R_UNBALANCED",
						  "ISC_R_NOMORE",
						  "ISC_R_INVALIDFILE",
						  "ISC_R_BADBASE64",
						  "ISC_R_UNEXPECTEDTOKEN",
						  "ISC_R_QUOTA",
						  "ISC_R_UNEXPECTED",
						  "ISC_R_ALREADYRUNNING",
						  "ISC_R_IGNORE",
						  "ISC_R_MASKNONCONTIG",
						  "ISC_R_FILENOTFOUND",
						  "ISC_R_FILEEXISTS",
						  "ISC_R_NOTCONNECTED",
						  "ISC_R_RANGE",
						  "ISC_R_NOENTROPY",
						  "ISC_R_MULTICAST",
						  "ISC_R_NOTFILE",
						  "ISC_R_NOTDIRECTORY",
						  "ISC_R_EMPTY",
						  "ISC_R_FAMILYMISMATCH",
						  "ISC_R_FAMILYNOSUPPORT",
						  "ISC_R_BADHEX",
						  "ISC_R_TOOMANYOPENFILES",
						  "ISC_R_NOTBLOCKING",
						  "ISC_R_UNBALANCEDQUOTES",
						  "ISC_R_INPROGRESS",
						  "ISC_R_CONNECTIONRESET",
						  "ISC_R_SOFTQUOTA",
						  "ISC_R_BADNUMBER",
						  "ISC_R_DISABLED",
						  "ISC_R_MAXSIZE",
						  "ISC_R_BADADDRESSFORM",
						  "ISC_R_BADBASE32",
						  "ISC_R_UNSET",
						  "ISC_R_MULTIPLE",
						  "ISC_R_WOULDBLOCK",
						  "ISC_R_COMPLETE",
						  "ISC_R_CRYPTOFAILURE",
						  "ISC_R_DISCQUOTA",
						  "ISC_R_DISCFULL",
						  "ISC_R_DEFAULT",
						  "ISC_R_IPV4PREFIX",
						  "ISC_R_TLSERROR",
						  "ISC_R_HTTP2ALPNERROR" };

#define ISC_RESULT_RESULTSET	  2
#define ISC_RESULT_UNAVAILABLESET 3

static isc_once_t once = ISC_ONCE_INIT;
static resulttable_list_t description_tables;
static resulttable_list_t identifier_tables;
static isc_rwlock_t lock;

static isc_result_t
register_table(resulttable_list_t *tables, unsigned int base,
	       unsigned int nresults, const char **text, int set) {
	resulttable *table;

	REQUIRE(base % ISC_RESULTCLASS_SIZE == 0);
	REQUIRE(nresults <= ISC_RESULTCLASS_SIZE);
	REQUIRE(text != NULL);

	/*
	 * We use malloc() here because we we want to be able to use
	 * isc_result_totext() even if there is no memory context.
	 */
	table = malloc(sizeof(*table));
	if (table == NULL) {
		return (ISC_R_NOMEMORY);
	}
	table->base = base;
	table->last = base + nresults - 1;
	table->text = text;
	table->set = set;
	ISC_LINK_INIT(table, link);

	RWLOCK(&lock, isc_rwlocktype_write);

	ISC_LIST_APPEND(*tables, table, link);

	RWUNLOCK(&lock, isc_rwlocktype_write);

	return (ISC_R_SUCCESS);
}

static void
initialize_action(void) {
	isc_result_t result;

	isc_rwlock_init(&lock, 0, 0);
	ISC_LIST_INIT(description_tables);
	ISC_LIST_INIT(identifier_tables);

	result = register_table(&description_tables, ISC_RESULTCLASS_ISC,
				ISC_R_NRESULTS, description,
				ISC_RESULT_RESULTSET);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "register_table() failed: %u", result);
	}

	result = register_table(&identifier_tables, ISC_RESULTCLASS_ISC,
				ISC_R_NRESULTS, identifier,
				ISC_RESULT_RESULTSET);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "register_table() failed: %u", result);
	}
}

static void
initialize(void) {
	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);
}

static const char *
isc_result_tomany_helper(resulttable_list_t *tables, isc_result_t result) {
	resulttable *table;
	const char *text;
	int index;

	initialize();

	RWLOCK(&lock, isc_rwlocktype_read);

	text = NULL;
	for (table = ISC_LIST_HEAD(*tables); table != NULL;
	     table = ISC_LIST_NEXT(table, link))
	{
		if (result >= table->base && result <= table->last) {
			index = (int)(result - table->base);
			text = table->text[index];
			break;
		}
	}
	if (text == NULL) {
		text = "(result code text not available)";
	}

	RWUNLOCK(&lock, isc_rwlocktype_read);

	return (text);
}

const char *
isc_result_totext(isc_result_t result) {
	return (isc_result_tomany_helper(&description_tables, result));
}

const char *
isc_result_toid(isc_result_t result) {
	return (isc_result_tomany_helper(&identifier_tables, result));
}

isc_result_t
isc_result_register(unsigned int base, unsigned int nresults, const char **text,
		    int set) {
	initialize();

	return (register_table(&description_tables, base, nresults, text, set));
}

isc_result_t
isc_result_registerids(unsigned int base, unsigned int nresults,
		       const char **ids, int set) {
	initialize();

	return (register_table(&identifier_tables, base, nresults, ids, set));
}
